Bell cap aerosol adaptor

ABSTRACT

A method of testing an air sample and/or testing equipment may comprise introducing aerosolized sample particles into an air flow to create sample air upstream from an air quality sampling device. The method may include introducing the sample air to an offset sample inlet of a bell cap inlet adaptor coupled to a sample tube. The method may include merging at least a portion of the introduced sample air with axially flowing air with little to no turbulence based on the geometry of the bell cap inlet adaptor and/or a containment cavity. The method may include introducing at least a portion of the sample air into the sample tube. Next, a test of at least one of the quality of the sample air and/or the functionality of the bell cap inlet may be performed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of, and claims priority to, and thebenefit of U.S. patent application Ser. No. 14/335,775, filed on Jul.18, 2014, and entitled “BELL CAP AEROSOL ADAPTOR” which is incorporatedby reference herein in its entirety.

FIELD

The present disclosure relates to testing systems, and more particularlyto air quality detector testing systems

BACKGROUND

The environment needed to make an accurate measurement of air quality(e.g., using a biological weapons detector testing system) often reliesupon very large facilities to approximate open air scenarios. Theselarge open facilities may be wasteful for the sample. Other restrictionsin the containment vessel volume and geometry may introduce unwanted airturbulence.

SUMMARY

According to various embodiments, a bell cap inlet adaptor is disclosedherein. The bell cap inlet adaptor may comprise a sample inlet in airflow communication with a containment cavity. The containment cavity maybe in fluid communication with an inlet to a sample tube. Air drawnthrough the sample tube may impart a cyclonic flow of air within thecontainment cavity. The sample tube may be offset from the axis of thecontainment cavity.

According to various embodiments, a method of testing an air sampleand/or testing equipment may comprise introducing aerosolized sampleparticles into an air flow to create sample air upstream from an airquality sampling device. The method may include introducing the sampleair to an offset sample inlet of a bell cap inlet adaptor coupled to abell cap inlet. The method may include merging at least a portion of theintroduced sample air with axially flowing air with little to noturbulence based on the geometry of the bell cap inlet adaptor and thebell cap inlet. The method may include introducing at least a portion ofthe sample air into the bell cap inlet. Next, a test of at least one ofthe quality of the sample air and/or the functionality of the bell capinlet may be performed.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the present disclosure is particularly pointed outand distinctly claimed in the concluding portion of the specification. Amore complete understanding of the present disclosure, however, may bestbe obtained by referring to the detailed description and claims whenconsidered in connection with the drawing figures, wherein like numeralsdenote like elements.

FIG. 1 depicts a cross-sectional illustration of a state of the art bellcap air quality and/or biological weapon detector testing system.

FIG. 2A depicts a cross-sectional top view illustration of a bell capaerosol adaptor air quality and/or biological weapon detector testingsystem in accordance with various embodiments.

FIG. 2B depicts a cross-sectional side view illustration of a bell capaerosol adaptor air quality and/or biological weapon detector testingsystem in accordance with various embodiments.

FIG. 3 is a flow diagram of a testing method via a bell cap aerosoladaptor air quality and/or biological weapon detector testing system inaccordance with various embodiments.

DETAILED DESCRIPTION

The detailed description of exemplary embodiments herein makes referenceto the accompanying drawings, which show exemplary embodiments by way ofillustration and their best mode. While these exemplary embodiments aredescribed in sufficient detail to enable those skilled in the art topractice the disclosure, it should be understood that other embodimentsmay be realized and that logical changes may be made without departingfrom the spirit and scope of the disclosure. Thus, the detaileddescription herein is presented for purposes of illustration only andnot of limitation. For example, the steps recited in any of the methodor process descriptions may be executed in any order and are notnecessarily limited to the order presented. Furthermore, any referenceto singular includes plural embodiments, and any reference to more thanone component or step may include a singular embodiment or step.

A common type of inlet for air quality and/or biological weapondetectors is the “bell cap” (See FIG. 1). Conventional bell cap inlet100 testing systems have the advantage of being omnidirectional and easyto manufacture. Testing a system with a conventional bell cap inlet 100in such a way as to control the sample losses is not trivial.Traditionally, a large enclosure that completely envelopes theconventional bell cap inlet 100 is used to ensure that aerosol lossesdue to turbulence are minimized. For systems with inlet flow rates inthe hundreds of liters per minute, this enclosure (i.e., room built fortesting the device) may be several feet across or losses of sample areobserved. Indoor testing of these systems is often space constrained soa smaller interface that still allows losses to be minimized isutilized.

Thus, testing of air quality and/or biological detectors with aconventional bell cap inlet 100 is either very space intensive orsubject to uncontrolled losses in sample efficiency. Use of theconventional bell cap inlet 100 also allows the losses inherent in thebell cap itself to be characterized independent of external effects suchas wind speed or boundary layer conditions that may occur in an outdoorsetting. It is desirable to develop a system and method to overcomethese concerns.

According to various embodiments and with reference to FIGS. 2A and 2B,a bell cap inlet adaptor 200 interface solves these and other concerns.Bell cap inlet adaptor 200 uses a velocity of incoming sample air andalready present cyclonic flow within the bell cap inlet adaptor 200 toensure aerosolized sample particles are driven to the sample tube inlet290 of the sample tube 250 rather than lost to the peripheral structuresof the bell cap inlet adaptor 200 or testing facility environment. Inthis way, the flows of air and the design of the shape of thecontainment cavity 240 minimize turbulence inside the containment cavity240. The cyclonic flow of air within the containment cavity 240 may bedue to an upstream fan or other device pulling air towards the roundedbell shaped top 295 of the bell cap inlet adaptor 200 to the sample tubeinlet 290. The sample inlet 225 of the bell cap inlet adaptor 200 istangentially offset to one side from the generally bowl shapedcontainment cavity 240 vessel. Stated another way, the sample inlet 225may be contained within one quadrant formed by an X and Y plane passingthrough the center axis of the sample tube 250. In this way, the sampletube inlet does not surround the perimeter of the sample tube 250. Theoffset is such that sample air enters the sample inlet 225 and acts as a“sheath flow” against the air already present in the containment cavity240. As used herein “sheath flow” refers to a flow of air withcharacteristics such that, when it merges with a second flow of air, itintroduces minimal turbulence in the second flow of air. In this way,the flow of sample air entering sample inlet 225 flows seamlessly intothe cyclonic flow of air within the containment cavity 240. Thus, theaxial flow with the system, and in particular within the containmentcavity 240, is substantially maintained in response to the sample airbeing introduced into the containment cavity 240 via the sample inlet225. Sample inlet 225 may be a single location on a side of the bell capinlet adaptor 200. This in contrast to the inlet location of aconventional bell cap inlet 100 which is in general, a circumferentialslot which surrounds the internal sample tube 250. Stated another way,as can be seen in FIG. 2A, the sample inlet 225 may extend from theperimeter of the containment cavity 240 at a single location rather thanaround the around the perimeter of the sample tube 250 as inconventional bell cap inlets 100.

As mentioned above, the cyclonic flow rate of air within the containmentcavity 240 may be a design constraint on the shape of the bell. The twoflows (e.g., the flow entering sample inlet 225 and the concentric flowwithin containment cavity 240 around sample tube 250) are configured tobe velocity matched to prevent and/or reduce the presence of turbulenceand the accompanying loss of sample due to unintended interactions, suchas unintended wall interactions within bell cap inlet adaptor 200(surface 230 or outer surface 235 of sample tube 250). Sample tube 250may be separate from and pass through (i.e. internal to) containmentcavity 240. Vertically, the top of the containment cavity 240 is matchedto the bottom of the bell cap inlet adaptor 200 to form a seamlessinteraction providing little to no dead space for sample loss.

The bell cap inlet adaptor 200 interface may be configured for particlesize discrimination. In this way, bell cap inlet adaptor 200 interfaceis configured for testing at about the 1 to 10 micrometer (μm) level(3.937×10⁻⁵ inches to 3.937×10⁻⁴ inches). Thus, the bell cap inletadaptor 200 interface may be configured to substantially rejectparticles larger than about 10 microns (˜0.00039 inches), as describedin more detail below.

According to various embodiments and with continued reference to FIGS.2A and 2B, a generally circular sample inlet 225 may be configured toreceive sample air. This may be through a tube. Though they may bedifferent distances, the width “Y” of the sample inlet 225 may be, ingeneral, substantially equal to the distance from the outer surface 235of sample tube 250 to surface 230 (See distance “X” of FIG. 2A).

The bell cap inlet adaptor 200 is configured for a continuous draw ofair and/or sample air during a test. As the air and/or sample air enterssample inlet 225 a portion of the sample air makes a gradual turn up (inthe Y direction as shown in FIG. 2B) into the neck of the bell captowards the top 295 of the bell cap inlet adaptor 200, and a portion ofthe sample air follows the curve of the bell cap inlet adaptor 200 intocontainment cavity 240. Thus, as a portion of the combination of air andsample air is transferred up (in the Y direction as shown in FIG. 2B)and towards the top 295 of the bell cap inlet adaptor 200 a second,generally smaller portion of air and sample air follows the curve of thebell cap inlet adaptor 200 in the containment cavity 240. The design ofthe offset of the sample inlet 225 and the offset of the position ofsample tube 250 within bell cap inlet adaptor 200 is configured tomaintain axial flow and/or reduce turbulence of sample air entering thecontainment cavity 240. The distance from the outer surface 235 ofsample tube 250 to surface 230 may be no larger than twice as large nearthe sample inlet 225 (See distance “2X” and distance “X” of FIG. 2A,where “X” depicts a minimum distance). The distance “X” may be be sizedbased on expected or intended flow rate.

In various embodiments, bell cap inlet adaptor 200 assists with thetesting of the design of bell cap inlet 100. Bell cap inlet adaptor 200may reduce the points of introduction of a sample to a single location(e.g., the sample inlet 225). In this way, the testing environment maybe reduced significantly. Additionally, flow into the bell cap inletadaptor 200 may be controlled.

According to various embodiments and with reference to FIG. 3, a methodof testing an air sample and/or testing equipment may compriseintroducing aerosolized sample particles into an air flow to createsample air upstream from an air quality sampling device (Step 310). Themethod may include introducing the sample air to an offset sample inletof a bell cap inlet adaptor 200 coupled to a sample tube (Step 320). Themethod may include merging at least a portion of the introduced sampleair with axially flowing air with little to no turbulence based on thegeometry of the bell cap inlet adaptor 200 (Step 330). The method mayinclude introducing at least a portion of the sample air into the sampletube (Step 340). Next, a test of at least one of the quality of thesample air and/or the functionality of the air quality sampling device,such as bell cap inlet adaptor 200, may be performed (Step 350).

Benefits, other advantages, and solutions to problems have beendescribed herein with regard to specific embodiments. Furthermore, theconnecting lines shown in the various figures contained herein areintended to represent exemplary functional relationships and/or physicalcouplings between the various elements. It should be noted that manyalternative or additional functional relationships or physicalconnections may be present in a practical system. However, the benefits,advantages, solutions to problems, and any elements that may cause anybenefit, advantage, or solution to occur or become more pronounced arenot to be construed as critical, required, or essential features orelements of the disclosure. The scope of the disclosure is accordinglyto be limited by nothing other than the appended claims, in whichreference to an element in the singular is not intended to mean “one andonly one” unless explicitly so stated, but rather “one or more.”Moreover, where a phrase similar to “at least one of A, B, or C” is usedin the claims, it is intended that the phrase be interpreted to meanthat A alone may be present in an embodiment, B alone may be present inan embodiment, C alone may be present in an embodiment, or that anycombination of the elements A, B and C may be present in a singleembodiment; for example, A and B, A and C, B and C, or A and B and C.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “various embodiments”, “oneembodiment”, “an embodiment”, “an example embodiment”, etc., indicatethat the embodiment described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases are not necessarily referring to the same embodiment.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is submitted that it iswithin the knowledge of one skilled in the art to affect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described. After reading the description, itwill be apparent to one skilled in the relevant art(s) how to implementthe disclosure in alternative embodiments. Different cross-hatching isused throughout the figures to denote different parts but notnecessarily to denote the same or different materials.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element herein is to be construed under theprovisions of 35 U.S.C. 112(f), unless the element is expressly recitedusing the phrase “means for.” As used herein, the terms “comprises”,“comprising”, or any other variation thereof, are intended to cover anon-exclusive inclusion, such that a process, method, article, orapparatus that comprises a list of elements does not include only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus.

What is claimed is:
 1. A method of testing aerosolized sample particlescomprising: introducing aerosolized sample particles into an air flow tocreate sample air upstream from an air quality sampling device;introducing the sample air to a sample inlet of a bell cap inlet adaptorcoupled to a sample tube; merging a first portion of the introducedsample air with axially cyclonic flowing air with low turbulence in thebell cap inlet adaptor; introducing a second portion of the sample airinto the sample inlet; and testing at least one of a quality of thesample air and/or a functionality of the bell cap inlet adapter with theair quality sampling device, wherein the sample inlet comprises a widththat is substantially equal to a shortest distance from an outer surfaceof the sample tube to an internal surface of the bell cap inlet adaptor,the sample tube is offset so as to not be concentric with the bell capinlet adaptor, and a distance from the outer surface of the sample tubeto an internal surface of the bell cap inlet adaptor at a locationopposite the sample tube from a location of the shortest distance fromthe outer surface of the sample tube to the internal surface of the bellcap inlet adaptor, within a same horizontal plane, is no larger thantwice the width of the sample inlet.
 2. The method of testing accordingto claim 1, further comprising parsing the first portion of sample airinto a third portion of sample air and a fourth portion of sample air;flowing the fourth portion of sample air around the sample tube within acontainment cavity; and introducing the third portion of the sample airinto the sample tube after the third portion of the sample air hastraveled around a portion of the perimeter of the sample tube.
 3. Themethod of testing according to claim 1, further comprising introducingat least a portion of the second portion of the sample air into thesample tube.
 4. The method of testing according to claim 1, furthercomprising positioning the sample tube such that the center axis of thesample tube is different than the center axis of a containment cavitysurrounding the sample tube.
 5. The method of testing according to claim4, further comprising offsetting the sample inlet tangentially from thecontainment cavity.
 6. The method of testing according to claim 1,wherein the sample air entering the sample inlet acts as a sheath flowagainst the axially cyclonic flowing air within a containment cavity. 7.The method of testing according to claim 1, further comprising impartingthe cyclonic flowing air within a containment cavity via the air qualitysampling device.